Question

If sin(A+B)=1/2,cos(A+B)=1/2,0degreelessthan A+B less than or equal to 90degree ,A+greater than B, find A

Answer 1

Please note that the question given has an error

Because sin(A+B)=1/2 and cos (A+B) = 1/2 is not possible as this would mean

30=A+B (sin 30 = 1/2)

60=A+B (cos 60 = 1/2)

taking the question as sin(a-b)=1/2 and cos(a+b)=1/2

As sin 30=1/2 and cos 60=1/2

a-b=30    --(1)

a+b=60   --(2)

Adding 1,2

2a=90

a=45

From equation 1

a-b=30

45-b=30

b=15

Hence a=45 , b=15